SMTP

TCP Port 25, 587 (SSL)

Mail Relay

Firewall rule that blocks port 25 outbound (and inbound) and log other ports.

FQDN = FULLy QUalified Domain Name ad01.joshua.local

EHLO = Asks the mail server for any extensions

Server extension SMTP-AUTH

HELO = Ask the server if it is the mail server.

MAIL = Specifies who the email is from.

RCPT = Recipient that is receiving the email.

DATA = Data from email is placed here